I can confirm this bug. Here is a screenshot of the error message I get when trying to run gdmsetup on Ubuntu Dapper Beta (upgraded to from Ubuntu Dapper Flight March 10 2006 64bit)
http://img280.imageshack.us/img280/1095/screenshotgdmsetup5gc.png -- can't start gdmsetup, error https://launchpad.net/bugs/42080 -- desktop-bugs mailing list desktop-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/desktop-bugs
